Cochleate delivery vehicles are a broad-based technology for the delivery of a wide range of bioactive therapeutic products. Cochleate delivery vehicles are stable phospholipid-cation precipitates composed of simple, naturally occurring materials, for example, phosphatidylserine and calcium.
The bilayer structure of cochleates provides protection from degradation for associated, or “encochleated.” molecules. Since the entire cochleate structure is a series of solid layers, components within the interior of the cochleate structure remain substantially intact, even though the outer layers of the cochleate may be exposed to harsh environmental conditions or enzymes. This includes protection from digestion in the stomach.
Taking advantage of these unique properties, cochleates have been used to mediate and enhance the oral bioavailability of a broad spectrum of important but difficult to formulate biopharmaceuticals, including compounds with poor water solubility, protein and peptide drugs, and large hydrophilic molecules. For example cochleate-mediated oral delivery of amphotericin B, large DNA constructs/plasmids for DNA vaccines and gene therapy, peptide formulations, and antibiotics such as clofazimine has been achieved.
Cochleates can be stored in cation-containing buffer, or lyophilized to a powder, stored at room temperature, and reconstituted with liquid prior to administration. Lyophilization has no adverse effects on cochleate morphology or functions. Cochleate preparations have been shown to be stable for more than two years at 4° C. in a cation-containing buffer, and at least one year as a lyophilized powder at room temperature.
Cochleates can be prepared by several methods, such as trapping or hydrogel methods (International Application Publication No. WO 03/082209, the entire content of which is incorporated herein by reference).
Soy PS is sold in health food stores as a nutritional supplement. Non-purified (40%) PS has been used and studied as a nutritional supplement and as a component that has a beneficial effect on enhancing the brain functions in elderly people (Villardita C et al., Clin. Trials J. 24, 1987, 84-93).
Although non-purified soy PS (NSPS) has been sold and studied on patients, NSPS (or low purity PS) has never been used to make cochleates and to deliver a drug using these cochleates. As previously disclosed in WO 03/082209, NSPS does not form cochleates and that a purification process is needed to enhance the NSPS in the content of PS, until at least about 75% by weight of PS is reached, such percentage allowing the formation of cochleates.